Imaging of radiocesium uptake dynamics in a plant body by using a newly developed high-resolution gamma camera. (January 2016)

• Record Type: Journal Article
• Authors: Kawachi, Naoki; Yin, Yong-Gen; Suzui, Nobuo; Ishii, Satomi; Yoshihara, Toshihiro; Watabe, Hiroshi; Yamamoto, Seiichi; Fujimaki, Shu
• Is Part Of: Journal of environmental radioactivity. Volume 151:Part 2(2016:Jan.)
• Page Start: 461
• Page End: 467
• Publication Date: 2016-01
• Subjects: Gamma camera -- Imaging -- Radiocesium -- 137Cs -- Plant -- Soybean; PETIS positron-emitting tracer imaging system -- PET positron emission tomography -- RRIS real-time radioisotope imaging system -- Ce:GAGG Ce-doped Gd3Al2Ga3O12 -- FWHM full width at half-maximum; Radioactivity -- Periodicals; Radiation, Background -- Periodicals; Radioecology -- Periodicals; Radioactive pollution -- Periodicals; Environmental Pollutants -- Periodicals; Radioactive Pollutants -- Periodicals; Radioactivity -- Periodicals; Radioécologie -- Périodiques; Pollution radioactive -- Périodiques; Fond de rayonnement -- Périodiques; 539.752
• DOI: 10.1016/j.jenvrad.2015.04.009
• Languages: English
• ISSNs: 0265-931X

Abstract

Abstract: We developed a new gamma camera specifically for plant nutritional research and successfully performed live imaging of the uptake and partitioning of 137 Cs in intact plants. The gamma camera was specially designed for high-energy gamma photons from 137 Cs (662 keV). To obtain reliable images, a pinhole collimator made of tungsten heavy alloy was used to reduce penetration and scattering of gamma photons. A single-crystal scintillator, Ce-doped Gd3 Al2 Ga3 O12, with high sensitivity, no natural radioactivity, and no hygroscopicity was used. The array block of the scintillator was coupled to a high-quantum efficiency position sensitive photomultiplier tube to obtain accurate images. The completed gamma camera had a sensitivity of 0.83 count s −1 MBq −1 for 137 Cs with an energy window from 600 keV to 730 keV, and a spatial resolution of 23.5 mm. We used this gamma camera to study soybean plants that were hydroponically grown and fed with 2.0 MBq of 137 Cs for 6 days to visualize and investigate the transport dynamics in aerial plant parts. 137 Cs gradually appeared in the shoot several hours after feeding, and then accumulated preferentially and intensively in growing pods and seeds; very little accumulation was observed in mature leaves. Our results also suggested that this gamma-camera method may serve as a practical analyzing tool for breeding crops and improving cultivation techniques resulting in low accumulation of radiocesium into the consumable parts of plants. Graphical abstract: Highlights: We developed a gamma camera specifically for plant nutritional research. Live imaging of the uptake and partitioning of 137 Cs in soybeans was performed. 137 Cs gradually appeared in the shoot about 12 h after feeding. 137 Cs accumulated in the growing pods and seeds but little in the mature leaves.